The present invention relates to a method for handling drilling rods and tubular wellbore casing elements; more in detail, it relates to a method for automatic handling of drilling rods and tubular wellbore casing elements, to the excavation equipment thereof, and to the computer program associated therewith.
It is known that traditional drilling machines use drilling rods which are driven in series one after the other into a main well.
It is also known that traditional drilling machines are installed with a drilling head above a main well, which is flanked by a service well, known in the art as mouse hole, into which the drilling rods, after having been picked up by a rod handler from a drilling rod container, are temporarily stored waiting for being picked up by the machine's drilling head, which then translates again over the main well with the rod just picked up from the mouse hole.
Traditionally, the process of picking up from the service hole the rods to be subsequently driven into the series of rods in the main well is carried out through manual steps which require the attention of an operator at the machine's controls, as well as the presence of an assistant on the drill floor, who does the work of manually greasing the threads of the drilling rods and of guiding the rods during the initial screwing step.
These manual operations are not exempt from troubles and dangers. In fact, mistakes may be made by the operator at the machine's controls due to lack of attention, which mistakes may lead to malfunctions or may cause dangerous situations to arise for the assistant on the drill floor. Moreover, the manually greased threads may suffer from excess of or unevenly distributed grease. In both cases, problems may arise at the threaded connections between the drilling rods.
Document U.S. Pat. No. 4,042,123 discloses a method for automatic handling of drilling rods from an auxiliary retaining means to a main well by means of a handling system. However, U.S. Pat. No. 4,042,123 does not teach any steps of picking up drilling rods through a drill head, also known as “top drive”.
In the event of an explosion or uncontrolled leakage of fluids and gases (also known as “blow-out”), there is a concrete risk that the outflow of fluids and gases from the last rod at the top of the well cannot be controlled.